A printing apparatus (for example, an ink jet printer) which a printing material container (for example, an ink cartridge) is attached to and executes printing is desired to be automatically capable of determining whether a printing material container is attached thereto. Also, A printing apparatus, for example, which plural types of printing material containers can be attached to and can print in accordance with the type of the printing material container is desired to be automatically capable of determining the type of the printing material container attached thereto. For example, known is the technique wherein the printing material container has a type-identifying mark indicating the type of the material container itself and the printing apparatus detect such type-identifying mark to determine the type of the material container.
However, above-mentioned technique has the risk that a circuit for detecting whether the printing material container is attached or the type of the printing material container may short with other circuit of the printing apparatus via contact point between the printing material container and the printing apparatus, for example, by the adhesion of conductive ink to the contact point. Especially, in the case the other circuit in the printing apparatus is a circuit which outputs high voltage (for example, a circuit driving the sensor for detecting the remaining ink level in the printing material container), such shorting may cause a trouble with the printing material container or the printing apparatus.